This invention relates to rolls for processing travelling web material, such as paper being made on a papermaking machine. More particularly, this invention relates to a so-called self-loading controlled deflection roll wherein pressure means is located within the roll to exert force against the inner peripheral surface of the roll shell at one or more locations to control the deflection of the roll shell along a longitudinally-extending line on its surface to be straight, or curved upwardly or downwardly, a controlled amount, as desired. Still more particularly, this invention relates to a self-loading controlled deflection roll wherein the roll shell is capable of being driven while simultaneously being moved laterally, or transversely, relative to its longitudinal axis.
Self-loading controlled deflection rolls are known. Examples are shown and described in U S. Pat. Nos. 3,885,283, 4,048,701 and 4,520,723. There are also many arrangements for driving controlled deflection rolls. These designs are often complicated due to the fact that the roll shell must be driven relative to its stationary support beam. This is further complicated by the fact that the roll shell must accommodate some flexing which occurs during operation of its controlled deflection structure, and the roll surface must be capable of moving into, and out of, nip engagement with a mating roll.
Prior self-loading controlled deflection rolls utilize self-aligning bearings on either end to accommodate the small, but significant, flexule motion of the roll shell about an axis transverse to its axis of rotation. Prior self-loading controlled deflection rolls also utilize a drive gearbox which requires its own bearings to support it independent of the roll shell.
Some prior self-loading controlled deflection rolls utilize sliding collars, or yokes, on which the inner race of the bearings on which the roll shell is rotatably mounted are in turn mounted to the sliding yokes to provide the lateral movement of the roll shell relative to the stationary roll shaft, or support beam. Such an arrangement is shown and described in the Biondetti, U.S. Pat. No. 3,885,283. This arrangement requires close tolerances for accurate operation, but these same close tolerances require costly accurate finishing of the surfaces brought into sliding engagement. On the other hand, loose tolerances can permit undesirable vibration.
Prior arrangements for driving a controlled deflection roll are very complex due to the need to support the stationary roll support beam while providing driving force to the roll shell. These arrangements often necessitated the use of triple-race bearings which are extremely expensive. Finally, controlled deflection rolls driven by any prior drive which is concentric with the longitudinal axis of the support beam can't accommodate lateral movement of the roll shell relative to the support beam.